1. Field of the Invention
The present invention relates to a voltage conversion apparatus, and more particularly, to a voltage conversion apparatus capable of adjusting system bandwidth according to operating state.
2. Description of the Prior Art
In general, a current mode DC-to-DC buck converter incorporates a compensating circuit following its internal error amplifier to maintain the stability of a closed-loop system. The phase margin of the closed-loop system needs a dominant pole to be maintained as stable. In a conventional way, a capacitor having a large capacitance (usually, at a nanometer scale) is attached to the compensation circuit to generate a dominant pole required by the closed-loop system. However, the capacitor having the large capacitance cannot be integrated into an IC. Thus, the IC needs pins for coupling the capacitor having the large capacitance in the implementation, which adversely affects the response speed of the entire closed-loop system as well as increases the manufacturing costs.